Inductively powered apparatus

ABSTRACT

An inductive power supply system for providing power to one or more inductively powered devices. The system includes a mechanism for varying the physical distance or the respective orientation between the primary coil and secondary coil to control the amount of power supplied to the inductively powered device. In another aspect, the present invention is directed to an inductive power supply system having a primary coil and a receptacle disposed within the magnetic field generated by the primary coil. One or more inductively powered devices are placed randomly within the receptacle to receive power inductively from the primary coil. The power supply circuit includes circuitry for adjusting the power supplied to the primary coil to optimize operation based on the position and cumulative characteristics of the inductively powered device(s) disposed within the receptacle.

This is a division of application U.S. application Ser. No. 10/357,932,filed Feb. 4, 2003 (now U.S. Pat. No. 7,126,450), which is acontinuation-in-part of U.S. application Ser. No. 10/133,860 entitled“Inductively Powered Lamp Assembly,” which was filed on Apr. 26, 2002(now U.S. Pat. No. 6,731,071) and is a continuation-in-part of U.S.application Ser. No. 09/592,194 entitled “Fluid Treatment System,” whichwas filed on Jun. 12, 2000 (now U.S. Pat. No. 6,436,299).

U.S. application Ser. No. 10/357,932 is also a continuation-in-part ofU.S. application Ser. No. 10/246,155 entitled “Inductively CoupledBallast Circuit,” which was filed on Sep. 18, 2002 (now U.S. Pat. No.6,825,620) and is a continuation-in-part of U.S. patent application Ser.No. 10/175,095 entitled “Fluid Treatment System,” which was filed onJun. 18, 2002 (now U.S. Pat. No. 6,673,250), which is acontinuation-in-part of U.S. patent application Ser. No. 09/592,194entitled “Fluid Treatment System,” which was filed on Jun. 12, 2000 (nowU.S. Pat. No. 6,436,299). U.S. patent application Ser. No. 09/592,194(now U.S. Pat. No. 6,436,299) claims the benefit under 35 U.S.C. §119(e)of U.S. provisional patent application Ser. No. 60/140,159 entitled“Water Treatment System with an Inductively Coupled Ballast,” which wasfiled on Jun. 21, 1999, and U.S. provisional patent application Ser. No.60/140,090 entitled “Point-of-Use Water Treatment System,” which wasfiled on Jun. 21, 1999.

U.S. application Ser. No. 10/357,932 is a continuation-in-part of U.S.application Ser. No. 29/165,043 entitled “Bulb,” which was filed on Aug.2, 2002 (now U.S. Pat. No. D476,095); U.S. application Ser. No.29/165,008 entitled “Bowl Lamp,” which was filed on Aug. 2, 2002 (nowU.S. Pat. No. D479,356); U.S. application Ser. No. 29/165,012 entitled“Bulb,” which was filed on Aug. 2, 2002 (now U.S. Pat. No. D476,094);U.S. application Ser. No. 29/165,005 entitled “Lamp,” which was filed onAug. 2, 2002 (now U.S. Pat. No. D479,892); U.S. application Ser. No.29/165,009 entitled “Bulb,” which was filed on Aug. 2, 2002 (now U.S.Pat. No. D475,471); and U.S. application Ser. No. 29/165,011 entitled“Chime,” which was filed on Aug. 2, 2002 (now U.S. Pat. No. D478,834).

BACKGROUND OF THE INVENTION

The present invention relates to wireless power supplies, and moreparticularly to inductively powered devices.

The principles of inductive power transfer have been known for manyyears. As a result of mutual inductance, power is wirelessly transferredfrom a primary coil (or simply “primary”) in a power supply circuit to asecondary coil (or simply “secondary”) in a secondary circuit. Thesecondary circuit is electrically coupled with a device, such as a lamp,a motor, a battery charger or any other device powered by electricity.The wireless connection provides a number of advantages overconventional hardwired connections. A wireless connection can reduce thechance of shock and can provide a relatively high level of electricalisolation between the power supply circuit and the secondary circuit.Inductive couplings can also make it easier for a consumer to replacelimited-life components. For example, in the context of lightingdevices, an inductively powered lamp assembly can be easily replacedwithout the need to make direct electrical connections. This not onlymakes the process easier to perform, but also limits the risk ofexposure to electric shock.

The use of inductive power transfer has, however, for the most part beenlimited to niche applications, such as for connections in wetenvironments. The limited use of inductive power transfer has beenlargely the result of power transfer efficiency concerns. To improve theefficiency of the inductive coupling, it is conventional to carefullydesign the configuration and layout of the primary and secondary coils.The primary and the secondary are conventionally disposed within closelymating components with minimal gap between the primary and thesecondary. For example, the primary is often disposed within a basedefining a central opening and the secondary is often disposed within acylindrical component that fits closely within the central opening ofthe base. This and other conventional constructions are design toprovide close coaxial and radial alignment between the primary coil andthe secondary coil. Several specific examples of patents that reflectthe conventional approach of providing a fixed, predetermined physicalrelationship between the primary and secondary coils include: U.S. Pat.No. 5,264,997 to Hutchisson et al, which discloses an inductive lampwith coaxial and closely interfitting primary and secondary coils; U.S.Pat. No. 5,536,979 to McEachern et al, which discloses an inductivecharging device in which the device to be charged is fitted closelywithin a cradle to position the coils in a fixed, predeterminedrelationship; U.S. Pat. No. 5,949,155 to Tamura et al, which discloses ashaver with adjacent inductive coils set in a fixed relationship; U.S.Pat. No. 5,952,814 to Van Lerberghe, which discloses an inductivecharger for a telephone wherein the physical relationship between theprimary and secondary coils is fixed; and U.S. Pat. No. 6,028,413 toBrockman, which discloses a charging device having a mechanical guidefor ensuring precise, predetermined alignment between the inductivecoils. The conventional practice of providing precise alignment betweenthe primary and secondary coil has placed significant limitation on theoverall design and adaptability of inductively powered devices. Further,in conventional inductive systems, the power supply circuit, whichdrives the primary coil, and the secondary circuit, which inductivelyreceives power from the primary, are designed and carefully tuned tomatch with one another to maximize the efficiency of the inductivecoupling. This too has placed significant limitations on the overalldesign and adaptability of inductively powered devices.

SUMMARY OF THE INVENTION

The aforementioned problems are overcome by the present inventionwherein an inductively powered device is provided with a mechanism forvarying the relative position between the primary and the secondary tocontrol the amount of power supplied to the load. In one embodiment, thepresent invention is incorporated into a dimmable lamp assembly in whicha primary is mounted to the lamp base and the secondary is mounted tothe lamp assembly. The brightness of the lamp is controlled by adjustingthe distance between the lamp assembly and the lamp base.

In a second embodiment, the present invention is incorporated into adimmable lamp assembly in which the lamp brightness is controlled byvarying the relative angular orientation of the primary and thesecondary. In this embodiment, the primary is generally ring-shaped andthe secondary is pivotally mounted within the ring. The lamp assemblyincludes a mechanical dimmer that rotates either the primary or thesecondary so that their relative angular orientation varies. Thevariation in relative orientation varies the amount of power transferredto the secondary, thereby varying the brightness of the lamp.

In another embodiment, the present invention is incorporated into a windchime having one or more lamps that vary in brightness based on themovement of the chimes. In this embodiment, a plurality of chimeassemblies is suspended within a primary coil, with each chime assemblybeing individually movable. Each chime assembly includes a secondarydisposed at its upper end within the magnetic field of the primary. Asthe wind blows, the chime assemblies swing with respect to the primary,thereby varying the locations and orientation of the secondary coilswithin the magnetic field of the primary. This causes the brightness ofthe wind chimes to vary in respond to the wind.

In yet another embodiment, the present invention provides an infinitelyadjustable power supply for use with electrically powered devices whereit is desirable to adjust the magnitude of power supplied to the device.The power supply includes an inductive coupling disposed between thepower supply and the load. The inductive coupling includes a primary anda secondary. The infinitely adjustable power supply also includes anadjustment mechanism for selectively varying the relative positionbetween the primary and the secondary, such as distance or angularorientation. The adjustment mechanism permits adjustment of the couplingcoefficient and consequently the magnitude of power induced in thesecondary and supplied to the load.

In a second aspect, the present invention is directed to an inductivepower supply station that is capable of providing power to a pluralityof inductive powered devices placed at random location and at randomorientations with respect to the primary. The inductive power supplystation generally includes a single primary arranged about a receptaclethat is capable of receiving randomly placed inductively powereddevices. The power supply circuit includes circuitry for adjusting thepower supplied to the primary as a function of the inductively powereddevices present in the receptacle. In one embodiment, the receptacle isa dish, bowl or similar structure in which one or more lamp assembliescan be placed to provide light. Each lamp assembly includes a secondarythat inductively receives power from the primary. The brightness of thelight can be controlled by varying the number of lamp assemblies placedin the receptacle and by moving the lamp assemblies within thereceptacle.

In a third aspect, the present invention provides a secondary with aplurality of coils that are arranged at different orientations. Themultiple coils permit the secondary to efficiently receive power whendisposed at different orientations with respect to the primary. In oneembodiment, a secondary with multiple coils is incorporated into aninductively powered lamp. The lamp assembly can receive maximum inducedpower when placed at different orientations within the magnetic field ofthe primary. In another embodiment, the lamp assembly includes aplurality of coils, each being electrically connected to a differentlight sources, for example, light sources of different colors. Byadjusting the orientation of the lamp assembly, the color of emittedlight can be varied by altering the respective brightness of theseparate light sources.

These and other objects, advantages, and features of the invention willbe readily understood and appreciated by reference to the detaileddescription of the preferred embodiment and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a desk lamp in accordance with anembodiment of the present invention.

FIG. 2 is a side elevational of the desk lamp of FIG. 1.

FIG. 3 is a partially sectional side elevational view of a portion ofthe desk lamp of FIG. 1.

FIG. 4 is an exploded view of a lamp assembly in accordance with oneembodiment of the present invention.

FIG. 5 is a schematic of a secondary circuit.

FIG. 6 is a perspective view of a rack-and-worm mechanical dimmer.

FIG. 7 is a perspective view of the base of a desk lamp showing a dial.

FIG. 8 is a perspective view of the base of a desk lamp showing aslider.

FIG. 9 is a perspective view of the base of a desk lamp showing arotating top.

FIG. 10 is a perspective view of an alternative mechanical dimmer.

FIG. 11 a is a side elevational view of an alternative desk lamp.

FIG. 11 b is an enlarged side elevational view of a portion of thealternative desk lamp of FIG. 11 a.

FIG. 12 is an enlarged perspective view of a portion of the alternativedesk lamp of FIG. 11 a showing the mechanical dimmer.

FIG. 13 is a side elevational view of a second alternative desk lamp.

FIG. 14 is an enlarged side elevational view of a portion of the secondalternative desk lamp of FIG. 13.

FIG. 15 is a sectional view of a portion of the second alternative desklamp of FIG. 13 showing the binding tab in the locked position.

FIG. 16 is a sectional view of a portion of the second alternative desklamp of FIG. 13 showing the binding tab in the open position.

FIG. 17 is a perspective view of a third alternative desk lamp.

FIG. 18 is a perspective view of the mechanical dimmer of the thirdalternative desk lamp of FIG. 17.

FIG. 19 is a sectional view of a portion of the mechanical dimmer of thethird embodiment.

FIG. 20 is a perspective view of a fourth alternative desk lamp.

FIG. 21 is a partially exploded perspective view of the thirdalternative desk lamp with portions removed to show the arm.

FIG. 22 is a partially exploded perspective view of the thirdalternative desk lamp with portions removed to show the primary housing.

FIG. 23 is a partially sectional side elevational view of a variablespeed fan incorporating an infinitely adjustable power supply inaccordance with an embodiment of the present invention.

FIG. 24 is a perspective view of a fifth alternative desk lamp.

FIG. 25 is a partially exploded perspective view of the fifthalternative desk lamp of FIG. 24.

FIG. 26 is a partially exploded side elevational view of replacementlamp base in accordance with an embodiment of the present invention.

FIG. 27 is a partially exploded side elevational view of an alternativereplacement lamp base.

FIG. 28 is a perspective view of a portion of the alternativereplacement lamp base of FIG. 27.

FIG. 29 is a perspective view of a wind chime in accordance with anembodiment of the present invention.

FIG. 30 is a partially exploded perspective view of a portion of thewind chime.

FIG. 31 is a partially exploded perspective view of a chime assembly.

FIG. 32 is a perspective view of a power supply station in accordancewith an embodiment of the present invention.

FIG. 33 is a partially exploded perspective view of the primary assemblyof the power supply station.

FIG. 34 is a partially exploded perspective view of the base of thepower supply station.

FIG. 35 is a partially exploded perspective view of a lamp assembly inaccordance with an embodiment of the present invention.

FIG. 36 is a perspective view of a secondary having multiple coils inaccordance with an embodiment of the present invention.

FIG. 37 is a perspective view of an assembly having multiple secondariesin accordance with an embodiment of the present invention.

FIG. 38 a is a schematic diagram of a secondary circuit for use with asecondary having multiple coils.

FIG. 38 b is a schematic diagram of an alternative secondary circuit foruse with a secondary having multiple coils.

FIG. 38 c is a schematic diagram of a second alternative secondarycircuit for use with a secondary having multiple coils.

FIG. 39 a is a schematic diagram of a circuit for use with an assemblyhaving multiple secondaries.

FIG. 39 b is a schematic diagram of an alternative circuit for use withan assembly having multiple secondaries.

FIG. 39 c is a schematic diagram of a second alternative circuit for usewith an assembly having multiple secondaries.

FIG. 39 d is a schematic diagram of a third alternative circuit for usewith an assembly having multiple secondaries.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention is directed to improvements in inductively powereddevices. In a first aspect, the present invention provides a inductivecoupling in which the relative position between the primary coil(“primary”) and the secondary coil (“secondary”) is selectively variedto permit control over the amount of power transferred to the secondaryand consequently to the inductively powered device. This aspect of theinvention is described in connection with various lamp configurations,for example, to permit control over the brightness of the light source.This aspect of the invention is also described in connection with otherelectrically powered devices where control over the amount of powersupplied to the inductively powered device is desired. In a secondaspect, the present invention is directed to an inductive power supplystation. In this aspect, the present invention provides a receptacle forreceiving one or more inductively powered devices at random locationsand at random orientations. In one embodiment of this aspect, thesecondary includes multiple coils arranged at different orientations sothat power can be more efficiently induced in the secondary withoutprecise alignment between the primary and secondary. In one embodiment,the secondary includes three coils oriented along the x, y and z axis ofa Cartesian coordinate system so that power can be induced in thesecondary regardless of the angular orientation of the secondary withrespect to the primary.

An inductively powered desk lamp 10 in accordance with an embodiment ofthe present invention is shown in FIG. 1. The lamp 10 generally includesa base 12, a lamp assembly 14 and a mechanical dimmer 16 (See FIG. 3).The base 12 includes a ballast and power supply circuit 18 that drives aprimary 20. The lamp assembly 14 includes a secondary circuit 22 havinga secondary 24 that is inductively powered by the primary 20 and thatapplies power to the light source 26. The mechanical dimmer 16 includesa movable arm 28 that is movably attached to the lamp base 12. Theprimary 20 is mounted to the arm 28 so that movement of the arm 28results in movement of the primary 20. The lamp assembly 14 is suspendedfrom the lamp base 12 with the secondary 24 positioned within theelectromagnetic field created by the primary 20. The arm 28 ismechanically movable to vary the position of the primary 20 with respectto the lamp assembly 14 (and consequently the secondary 24), therebyvarying the coupling coefficient between the primary 20 and secondary24. Changes in the coupling coefficient result in variation in the powertransferred to the lamp assembly 14 and ultimately in the brightness ofthe light source 26. This aspect of the present invention is describedin connection with a dimmable lamp 10. The present invention is,however, well-suited for use in virtually any application wherevariation in the amount of power transferred to the secondary circuit 20is desired. For example, as described in more detail below, the presentinvention may be used to provide infinitely adjustable control over theamount of power supplied to a device up to the capacity of the powersupply circuit.

As noted above, the desk lamp 10 of the illustrated embodiment generallyincludes a base 12, a lamp assembly 14 and a mechanical dimmer 16. Thelamp base 12 generally includes a pedestal 30, a shaft 32 and a primaryhousing 34. The pedestal 20 of the illustrated embodiment is generallydisc-shaped having a diameter of sufficient size to provide a stablesupport for the shaft 32 and lamp assembly 14, an internal void 31adapted to house the power supply circuit 18 and portions of themechanical dimmer 16. The shaft 32 extends upwardly from the pedestal toreceive the lamp assembly 14. In the illustrated embodiment, the shaft32 is somewhat “?”-shaped, providing an aesthetically pleasing visualappearance. The shaft 32 terminates at its upper end in a hook 36 orother connection element configured to receive the ring 38 of the lampassembly 14. The primary housing 34 is generally ring-shaped and ishollow to provide a shell or housing for the primary 20. The primaryhousing 34 is mounted to the arm 28 to support the primary 20 in aposition generally encircling the secondary housing 25 of the lampassembly 14. The illustrated pedestal 30 and shaft 32 are provided witha desired aesthetic appearance. The present invention is easily adaptedfor use with lamps of a wide variety of designs. Accordingly, the designand configuration of the illustrated base 12 should not be interpretedas a limitation on the present invention. The power supply circuit 18may be a conventional inductive power supply circuit, however, in oneembodiment, the power supply circuit 18 includes a resonance seekingballast, such as the ballast disclosed in U.S. application Ser. No.10/246,155 entitled “Inductively Coupled Ballast Circuit,” which wasfiled on Sep. 18, 2002, and is incorporated herein by reference. In theillustrated embodiment, the principle components of the power supplycircuit 18 are housed within the void 31 in pedestal 30, for example, asshown in FIG. 3. The location of the components of the power supplycircuit 18 may, however, vary from application to application dependingprimarily on the lamp design and desired aesthetics. For example, theprinciple components of the power supply circuit 18 can alternatively bedisposed at other locations in or on the pedestal 30 or may be disposedin or on the shaft 32. As a further alternative, some or all of thecomponents of the power supply circuit 18 can be integrated into a wallplug (not shown) for the lamp 10. In the illustrated embodiment, theprimary 20 is generally ring-shaped and is mounted within a generallyring-shaped primary housing 34. The primary housing 34 defines a centralopening 35 that is of sufficient dimension to receive at least a portionof the lamp assembly 14. The size, shape and orientation of the primary20 (and primary housing 34) can vary from application to applicationdepending in part on the specific design characteristics of the lamp orother inductive device. In the described embodiment, the primary 20 hasan inner diameter of 1.25 inches and includes 50 turns of wire 63wrapped circumferentially around a generally conventional plastic bobbin33. The wire 63 may be straight 26-gauge wire. Additionally, in thisparticular embodiment, the values of capacitors 271 and 272 in theabove-referenced patent application are 66 nF.

The lamp assembly 14 generally includes a light source 26, such as anincandescent bulb, that is powered by a secondary circuit 22 (See FIGS.4 and 5). In this embodiment, the light source 26 is custom formed toprovide the desired aesthetic appearance. The upper end of the lightsource 26 is shaped to define a small ring 28 that permits the lightsource 26 to be hung from a hook 36 defined at the end of shaft 32. Thecustom-formed lamp of the illustrated embodiment is merely exemplary,and the light source 26 may vary from application to application asdesired. As an alternative to the custom-formed lamp 26, the lampassembly 14 may include a conventional lamp (not shown) that iscontained within a housing (not shown) designed to provide the desiredaesthetic appearance. For example, the custom-shaped light source 26 canbe replaced by a standard incandescent light source that is installedwithin an ornate and aesthetically pleasing housing. In this alternativeembodiment, the secondary circuit 22 may also be enclosed within thehousing.

As noted above, the lamp assembly 14 includes a secondary circuit 22that provides power to the lamp 26. The secondary circuit 22 includes asecondary 24 that is inductively driven by the primary 20. A schematicdiagram of the secondary circuit is shown in FIG. 5. In this embodiment,the light source 26 is a custom-formed incandescent 30-watt bulb. Thelight source 26 is electrically connected in series with the secondary24 and, if desired, a capacitor 60. In this embodiment, the secondary 24has a diameter of 0.25 inches and includes 24 turns of wire 64 wrappedcircumferentially around a generally conventional plastic bobbin 62. Thewire 64 may be straight 26-gauge wire. The optional capacitor 60 isintended to improve the power factor of the secondary circuit 22 byoffsetting the inductance of the secondary 24, as described in moredetail in U.S. application Ser. No. 10/133,860 entitled “InductivelyPowered Lamp Assembly,” which was filed on Apr. 26, 2002 and isincorporated herein by reference. In this embodiment, the capacitor 60includes a capacitance of 33 nF. The characteristics of the secondarycircuit 22, including the secondary 24 and the capacitor 60, may varyfrom application to application depending primarily on thecharacteristics of the light source and the power supply. In fact, asnoted above, the capacitor 60 is optional and may be eliminatedaltogether in some applications. Although this embodiment includes anincandescent light source 26, the present invention can alternativelyinclude essentially any other electromagnetic radiation emitting device,such as a gas discharge bulb or a light emitting diode.

As described above, the desk lamp 10 is provided with a mechanicaldimmer 16 for controlling the brightness of the light source 26. In theillustrated embodiment, the mechanical dimmer 16 is incorporated intothe base 12 and shaft 32 to provide vertical movement of the primaryhousing 34 (and consequently the primary 20) and vary the physicaldistance between the primary 20 and the secondary 24. As shown, theprimary housing 34 is mounted on movable arm 28. In this embodiment, thearm 28 extends through a vertical slot 50 in the shaft 32 and isconnected to the rack 72 of a rack-and-worm assembly 70. In thisembodiment, the lamp base 12 may include a dial 66 a (See FIG. 7), aslider 66 b (See FIG. 8) or a rotating top 66 c (See FIG. 9) forcontrolling movement of the mechanical dimmer 16. The rack-and-wormassembly 70 translates rotational movement of the dial 66 a, slider 66 bor rotating top 66 c into vertical movement of the primary 20 inaccordance with conventional mechanical principles. More specifically,movement of dial 66 a, slider 66 b or rotating top 66 c causes rotationof worm gear 74, which is rotatably fixed within the lamp base 12 orshaft 32. In the illustrated embodiment, dial 66 a is connected to wormgear 74 by spur gear 68. As a result, rotational movement of dial 66 acauses rotational movement of spur gear 68 and ultimately worm gear 74.Movement of worm gear 74 in turn causes vertical linear movement of therack 72 and consequently the primary 20. As perhaps best shown in FIG.6, the rack 72 includes longitudinal slots 73 that are interfitted withcorresponding ribs (not shown) on the interior of the shaft 32. Thisinterface permits vertical movement of the rack 72 within the shaft 32.Because of the non-reversible nature of a worm gear assembly (i.e. theworm 74 can move the rack 72, but the rack 72 cannot rotate the wormgear 74), it provides a “self-locking” mechanical dimmer 16. Theelectrical leads (not shown) running from the power supply circuit 18 tothe primary housing 34 are provided with sufficient slack to permit thedesired range of motion. Alternatively, sliding contacts (not shown) canbe provided to maintain an electrical connection between the powersupply circuit 18 and the primary 20 throughout the entire range ofmotion of the mechanical dimmer 16.

An alternative mechanical dimmer 80 is shown in FIG. 10. In thisalternative embodiment, the inner end of the arm 82 includes a nut 84that is movable mounted over a threaded rod 86. The height of the arm 82is adjusted by rotating the threaded rod 86, which causes the nut 84 tomove up and down the shaft of the rod 86. The rod 86 may be rotatedusing essentially any type of control, such as dial 66 a, slider 66 b orrotating top 66 c. As with the rack-and-worm embodiment described above,slack electrical leads, sliding contacts or other similar mechanisms canbe provided to maintain electrical connection throughout the desiredrange of motion of the arm 82.

The mechanical dimmer may alternatively be configured to providemovement of the lamp assembly 14 with respect to the primary 20. Thisalternative may be preferable in some applications because it maysimplify the electrical configuration of the system. More specifically,because there is no relative movement between the power supply circuit18 and the primary 20, wires or other electrical connections can be rundirectly from the power supply circuit 18 to the primary 20 without anyaccommodation for relative movement (e.g. slack electrical leads orsliding contacts). Further, because the lamp assembly 14 is selfcontained, there is no need to run electrical connections to the lampassembly 14. In one embodiment of the desk lamp 10′ manufactured inaccordance with this alternative, the shaft 32′ includes a plurality ofnotches 40 a-c′ capable of receiving the lamp assembly 14′ (See FIGS. 11a-b and 12). In this embodiment, the upper end of the lamp assembly 14′is provided with an enlarged ring 38′ capable of being fitted into thenotches 40 a-c′. As illustrated, the lamp assembly 14′ can be suspendedfrom different notches 40 a-c′ to vary the position of the secondaryhousing 25′ with respect to the primary housing 34′. This in turn variesthe brightness of the lamp assembly 14′. In a second embodiment of analternative desk lamp 10″, the shaft 32″ is manufactured from a flexiblematerial that is capable of bending to vary the position of the lampassembly 14″ with respect to the primary housing 34″, and consequentlythe position of the secondary with respect to the primary. In someapplications, the flexible shaft 32″ may have little or no resiliency sothat it remains in whatever position it is bent into under acted on. Inother applications, the flexible shaft 32″ may be resilient so that amechanism is required to hold the shaft 32″ in the desired position. Inone embodiment of this type of application shown in FIGS. 13-16, aweight 42″ is fitted over and movable along the shaft 32″ to set andmaintain the shaft 32″ at the desired bend (See FIGS. 13 and 16). In oneembodiment, the weight 42″ is fitted over the shaft 32″ and includes agenerally conventional, spring-loaded binding clip 50″ that selectivelylocks the weight in place on the shaft 32″. In operation, spring 52″biases the binding clip 50″ into a binding position on the shaft 32″. Tomove the weight, the binding clip 50″ is pushed against the bias ofspring 52″ into a released position in which the binding clip 50″ isfree to slide along the shaft 32″. In a third embodiment of the desklamp 10′″, a counterbalance assembly 44′″ is used to set the position ofthe lamp assembly 14′″. In this embodiment, the shaft 32′″ is preferablyhollow, defining an internal space (not shown) to contain thecounterbalance assembly 44′″. The lamp assembly 14′″ is suspended fromthe shaft 32′″ by a cable 48′″. The cable 48′″ extends through theinternal space in the shaft 32′″ and is fixed to the counterbalanceassembly 44′″. A ring 40′″ is mounted to the free end of the cable 48′″to interconnect with the lamp assembly ring 38′″. As best shown in FIG.18, the counterbalance assembly 44 generally includes a spring 50′″ (orother biasing mechanism) with a tension that offsets the weight of thelamp assembly 14′″. The counterbalance assembly 44 also includes a pairof rollers 52 a-b′″ that firmly entrap the cable 48′″. The rollers 52a-b′″ are fitted with Bellville washers 54 a-b′″ to provide a limitingbrake that retains the cable 48′″ in a given position (See FIG. 19). Byoffsetting the weight of the lamp assembly 14″, the counterbalanceassembly 44 holds the lamp assembly 14′″ in the position selected by theuser. This allows the user to set the brightness of the lamp assembly14′″ simply by raising or lowering the lamp assembly 14′″.Alternatively, the spring 50′″ can be replaced by a counterbalanceweight (not shown) having approximately the same weight as the lampassembly 14′″.

In a further alternative embodiment (not shown), the mechanical dimmermay include a mechanism for moving the secondary within the lampassembly rather than moving the entire lamp assembly. For example, thelamp assembly may include a secondary that is slidably movably mountedalong a fixed shaft so that the user can slide the secondary up or downthe shaft to control the brightness of the lamp assembly (not shown).Alternatively, the secondary may be rotatably mounted within thesecondary housing to permit changes to the angular orientation of thesecondary, for example, by mounting the secondary on a ball joint (notshown). Knobs or handles (not shown) may protrude through slots in thesecondary housing to facilitate the linear or angular movement. Themechanical dimmer may alternatively include a similar mechanism (notshown) for moving the primary within the primary housing.

An alternative inductively powered lamp 100 is shown in FIGS. 20-22. Inthis embodiment, the amount of power supplied to the secondary componentis controlled by varying the relative angular orientation of thesecondary 124 with respect to the primary 120. The lamp 110 generallyincludes a pedestal 130, a shaft 132 mounted to the pedestal 130 and anarm 133 pivotally mounted to the shaft 132. In one embodiment, lightsource 126 is located toward one end of arm 133, and a counterbalance150 is located toward the opposite end. The power supply circuit ispreferably contained primarily in the pedestal 130 and the shaft 132,and includes a primary 120 that is mounted toward the top of the shaft132 in a ring-shaped primary housing 134. The primary housing 134 may beassembled from injection molded halves 134 a-b. A support 140 extendsupwardly from the shaft 132 into the central opening defined by theprimary housing 134. The support 140 defines a concave cradle 142adapted to receive the arm 133. The arm 133 includes a sphere 146disposed at the center of gravity of the arm 133. The sphere 146 may beassembled from injection molded halves 146 a and 146 b, and includes anouter diameter that corresponds with the inner diameter of the cradle142. Accordingly, the arm 133 is mounted to the shaft 132 by resting itupon the support 140 with sphere 146 received in cradle 142. If desired,the stability of the arm 133 may be improved by heavily weighting thesphere 146. The illustrated connection permits pivotal movement of thearm 133 in essentially all directions. A variety of alternative jointscan be used to connect the arm 133 to the shaft 132. For example, astandard ball and socket or a standard universal joint can replace theillustrated connection. If desired, a connection providing only limitedmovement of the arm 133, such as only vertical or only horizontalmovement, may be used.

In operation, the arm 133 is pivotally moved with respect to the shaft132 causing a rolling action of sphere 146 within cradle 142. As the arm133 is moved, the secondary 124 pivots within the magnetic fieldgenerated by the primary 120. This varies the coupling coefficient andthe brightness of the light source 126. The secondary 124 and primary120 can be oriented to provide the brightest light at the desiredposition of the arm 133. For example, the light source 126 may be itsbrightest when the arm 133 is substantially horizontal and increasinglydim as the arm 133 is moved up or down out of the horizontal position.Alternatively, the light source 126 may become brighter as the arm 133is moved downward below horizontal. Counterbalance 150 is provided tocounter the weight of light source 126, thereby maintaining the relativeposition of arm 133 unless acted upon.

The previously described embodiments are directed to lightingapplications in which the brightness of the light source is controlledby mechanisms that vary the relative position of primary and secondary.The present invention is not, however, limited to lighting application.Rather, the present invention is well suited for use in essentially anyapplication when control over the amount of power supplied to a deviceis desired. In this aspect, the present invention provides an infinitelyadjustable inductive power supply. By providing a mechanism forcontrolling the position of the secondary with respect to the primary,the amount of power supplied through the inductive coupling can becontrolled. More specifically, by adjusting the distance between theprimary and the secondary or the angular orientation between the primaryand the secondary, the coupling coefficient of the inductive couplingcan be infinitely adjusted within the range of the inductive powersupply. In this aspect, the present invention not only provides aninfinitely adjustable power source, but it also provides isolationbetween the power supply and the inductively powered device, therebyproviding safety benefits.

An adjustable power supply in accordance with the present invention isdescribed in more detail in connection with the variable speed fan 200shown in FIG. 23. In the illustrated embodiment, the fan 200 includes aconventional electric motor 280 that is housing within a generallyconventional fan housing 282. The fan 200 includes a plurality of fanblades 284 a-c that are mounted to the rotor (not shown) of the electricmotor 280. The electric motor 280 receives power from a power supplycircuit 218 having a primary 220 and a secondary 224. The secondary 224is movably mounted adjacent to the primary 220 so that movement of thesecondary 224 can be used to selectively vary the coupling coefficientof the inductive coupling and, in turn, vary the power supplied to themotor 280. For example, in the illustrated embodiment, the secondary 224is mounted to adjustment rod 290. The adjustment rod 290 is movableinwardly and outwardly with respect to the fan housing, as indicated byarrow A, to move the secondary 224 with respect to the primary 220. As aresult, adjustment of the secondary 224 can be used to selectivelycontrol the speed of the fan 200. Although this embodiment includes amechanism for moving the secondary 224, the coupling coefficient canalternatively be adjusted by providing a mechanism for moving theprimary 220 or for moving both the primary 220 and the secondary 224. Asnoted above, adjustment of the coupling coefficient can be achieved byvarying the physical distance between the primary and the secondaryand/or by varying the relative angular orientation between the primaryand the secondary.

Although described in connection with a variable speed fan, theinfinitely adjustable power supply of the present invention is wellsuited for use in other applications where an adjustable power supply isdesired. For example, the power supply may be incorporated into abattery charger (not shown), where the magnitude of the charging poweris controlled by adjusting the relative position of the primary and thesecondary. As a further example, the power supply may be incorporatedinto an electric drill (not shown) or other electric power tool, wherethe power supplied to the electric motor is adjusted by selectivelyvarying the relative position between the primary and the secondary.

In another embodiment, a desk lamp 300 is provided with a lamp assembly314 that can be positioned in different orientations to vary thecharacteristics of the light output. In the embodiment illustrated inFIGS. 24 and 25, the desk lamp 300 includes a lamp assembly 314 that canbe positioned in either an upright or inverted position with the twopositions creating different lighting effects. As shown, the desk lamp300 includes a base 312 having a pedestal 330, a shaft 332 and a primaryhousing 334. The primary housing 334 encloses the primary 320 andprovides an annular structure for supporting the lamp assembly 314. Inthe illustrated embodiment, a transparent plate 340 is mounted withinthe primary housing 334 to receive the lamp assembly 314. The plate 340defines a central opening 342 to nest the lamp assembly 314. In thisembodiment, the lamp assembly 314 is generally “egg-shaped” having apair of light transmissive housing components disposed on opposite sidesof a support ring 360. More specifically, the lamp assembly 314 includesa transparent housing portion 362 and a translucent housing portion 364.A separate light source, such as incandescent bulbs, may be positionedwithin each housing portion 362 and 364 or a single light source may beprovided to cast light through both housing portions 362 and 364. Thehousing portions 362 and 364 each have an external diameter that issmaller than the internal diameter of the central opening 342 in theplate 340. The external diameter of the support ring 360 is, however,greater than the internal diameter of the central opening 342. As aresult, the lamp assembly 314 can be suspended within the centralopening 342 upon the support ring 360.

In use, the character of the light emitted by the lamp 300 can be variedby placing the lamp assembly 314 into the central opening 342 indifferent orientations. In particular, placing the lamp assembly 314with the transparent housing portion 362 facing downwardly causes thedesk lamp 300 to cast bright, clear light onto the surface below, whilecasting soft, diffuse light upwardly away from the surface. Invertingthe lamp assembly 314 and placing it with the translucent housingportion 364 facing downwardly causes the desk lamp 300 to cast soft,diffuse light downwardly onto the surface below, and bright, clear lightupwardly away from the surface. Variations in the light cast by the lamp300 can also be achieved by providing the housing portions 362 and 364with different physical and optical characteristics. For example, thetwo housing portions 362 and 364 can be manufactured from differentcolor materials, have different sizes or shapes or be formed withdifferent lens characteristics, such as variations in focus,magnification and diffusion. Alternatively, differences in the lightcast by the lamp 300 can be achieved by providing different lightsources within housing 362 and 364. For example, the two light sourcesmay have different wattage or be of different lamp types. In oneembodiment, housing 362 is manufactured from clear glass or polymer, andcontains a white incandescent bulb, while housing 364 is manufacturedfrom a translucent glass or polymer, and contains a blue LED.

If desired, the physical distance between the primary and secondary canalso be varied by placing the lamp assembly 314 into the central opening342 in different positions. If the secondary 324 is axially aligned withthe support ring 360, then the secondary 324 will be in substantiallythe same position with respect to the primary 320 regardless of whetherthe transparent portion 362 or the translucent portion 364 is facingupwardly. On the other hand, if the secondary coil 324 is axially offsetfrom the support ring 360, the physical distance between the primary 320and the secondary 324 will vary depending on the orientation of the lampassembly 314. The secondary 324 can be offset from the support ring 360in either direction depending on the position in which more light outputis desired.

In yet another aspect, the present invention is incorporated into areplacement lamp base 400 intended to work in existing screw-base lamps.As shown in FIG. 26, the lamp base 400 includes a housing 402 containinga power supply circuit 418 that drives a primary 420. In the illustratedembodiment, the housing 402 is manufactured from two injection-moldedhalves that close about the power supply circuit 418 and the primary420. The housing 402 also includes a screw base 404 that is generallyidentical to the existing screw-base of conventional incandescent lamps.The screw base 404 is fitted over a lower portion of the housing 402 sothat it can be easily screwed into a conventional lamp socket (notshown). Electrical leads (not shown) extend from the screw base 404 tothe power supply circuit 418 through corresponding openings in thehousing 402. The housing 402 defines a lamp receptacle 408 adapted toreceive an inductive lamp assembly 414. The receptacle 408 may include amechanical dimmer that permits the user to mechanically vary therespective position between the primary and the secondary (See FIGS. 27and 28). A mechanical dimmer is not, however, necessary, and thereceptacle 408 may include a bayonet fitting or other conventionalfitting to secure the lamp assembly 414 within the receptacle 408 in afixed position. In the alternative embodiment shown in FIGS. 27 and 28,the receptacle 408′ includes cams 410 a-b′ that permit the position ofthe lamp assembly 414′ to be mechanically varied. The cams 410 a-b′interact with corresponding cams 412 a-b′ on the undersurface of thesecondary housing 403′, as described in more detail below. The cams 410a-b′ and 412 a-b′ may be replaced by threads or other similar mechanisms(not shown) for mechanically selectively varying the depth of the lampassembly 414′ within the receptacle 408′. To help to retain the lampassembly 414 in the desired position within the receptacle 408, thereceptacle 408 and the secondary housing 403 are configured to befrictionally interfitted with one another. In this embodiment, aresilient o-ring 440 may be fitted around the secondary housing 403 toprovide a firm frictional interface. The o-ring 440 is preferablyseating within an annular recess (not shown) to help prevent it fromsliding up or down the housing 403. Alternatively, the o-ring 440 may befitted within an annular recess (not shown) in the receptacle 408. As afurther alternative, the mechanical dimmer may include a mechanism formoving the primary 420 within the housing 402 or the secondary 424within the secondary housing 403. For example, either coil may beslidably movable along its axis within its corresponding housing to varythe distance between the primary and the secondary, or either coil maybe pivotally movable within its housing to vary the angular orientationbetween the primary and the secondary. The power supply circuit 418 maybe generally identical to the power supply circuit 18 described above,with component values selected to match the desired light source orrange of light sources.

Referring now to FIG. 26, the lamp assembly 414 generally includes asecondary housing 403 that is adapted to be fitted within the lampreceptacle 408, a secondary circuit (not shown) contained within thesecondary housing 425, and a light source 426 protruding from thesecondary housing 425. The secondary housing 425 generally includes twoinjection molded halves that are closed around the secondary 424 and theremainder of the secondary circuit (not shown). As noted above, thesecondary housing 403′ of the alternative embodiment shown in FIG. 27includes cams 412 a-b′ on its undersurface to interact with the cams 410a-b′ of the receptacle 408. The cams 412 a-b′ may be eliminated orreplaced with other mechanical dimming mechanisms. The secondary circuitis preferably generally identical to the secondary circuit 22 describedabove, with its component values selected to correspond with the desiredlight source 426.

In an alternative embodiment, the present invention is incorporated intoinductively powered wind chimes 500 that provide both and audible andvisual response to the wind (See FIGS. 29-31). In general, the windchime 500 includes a primary housing 512 that is suspended from ahanging ring 504 and a plurality of chime assemblies 514 a-d that aresuspended from the hanging ring 504 within the center of the primaryhousing 512. The primary housing 512 is suspended from the hanging ring504 by wires 502 a-d or other similar components. The hanging ring 504is configured to permit the wind chimes 500 to be hung in a wide varietyof locations. In the illustrated embodiment, the primary housing 512includes two injection molded halves 512 a-b that house the primary 520(See FIG. 30). The power supply circuit (not shown) is contained withinthe wall plug (not shown). The power supply circuit 518 may be generallyidentical to the power supply circuit 18 described above, with componentvalues selected to match the desired light source or range of lightsources.

Each chime assembly 514 a-d is suspended within the center of theprimary housing 512 by a corresponding wire 506 a-d. The separate wires506 a-d permit each chime assembly 514 a-d to move freely in response tothe wind. Each chime assembly 514 a-d generally includes a chime housing530, a light source 526, a secondary circuit 522 and a chime 532. Thechime housing 530 of the illustrated embodiment includes an opaque upperhousing portion 530 a that is suspended from the corresponding wire 506a-d and a transparent lower housing portion 530 b that is mounted to theundersurface of the upper housing portion 530 a. The chime housing 530defines an internal space for containing the secondary circuit 522,including the secondary 524, the light source 526 and any desiredcapacitor 528. The secondary circuit 522 is housed within the upperportion 530 a where it is largely hidden from sight. The light source526 extends from the upper housing portion 530 a down into the lowerhousing portion 530 b. The chime 532 is a generally conventional chimeand is mounted to the lower end of each chime housing 530. As a result,as the chime assemblies 514 a-d move in the wind, the chimes 532 collidewith one another to create sound. At the same time, as each chimeassembly 514 a-d moves, its secondary 524 moves toward and away from theprimary 520. The movement of the secondary 524 within the magnetic fieldgenerated by the primary 520 varies the amount of power supplied to thelight source 526, and consequently the brightness of the light source526. More specifically, as a chime assembly 514 a-d moves closer to theprimary 520, the amount of power transferred by the primary 520 to thesecondary 524 increases and the light source 526 becomes brighter.Conversely, as a chime assembly 514 a-d moves away from the primary 520,the amount of power transferred to the secondary 524 decreases and thelight source 526 becomes dimmer. As a result, increased wind causesincreased movement of the chime assembly 514 a-d and increasedundulations in the brightness of the light sources 526.

In a further aspect, the present invention relates to an inductive powersupply station having a primary that inductively provides power to oneor more inductively powered devices, each having its own secondary coil.In the embodiment illustrated in FIGS. 32-35, the inductive power supplystation 600 generally includes a power receptacle 602 and a storagereceptacle 608 that are supported by a plurality of legs 606 a-c. Aprimary 620 is disposed around the power receptacle 602 to generate amagnetic field that provides inductive power to any inductive devices650 a-c placed within the power receptacle 602. In the describedembodiment, the primary 620 has a diameter of 6.5 inches and includes 50turns of wire 663 wrapped circumferentially around a generallyconventional plastic bobbin 633. The wire 663 may be litz wireconsisting of eight strands of 32-gauge insulated wire wrapped 1 turnper inch, which may provide the primary 620 with improved efficiency.The primary 620 is contained within primary housing 634. Referring nowto FIG. 33, the primary housing 634 includes two annular halves 634 aand 634 b that enclose the primary 620.

The power receptacle 602 is intended to receive a plurality of inductivedevices, such as lamp assemblies 614 a-b, at random locations and randomorientations. In the illustrated embodiment, the power receptacle 602 isbowl-shaped and is manufactured from a transparent or translucentmaterial, such as glass or plastic. The bowl-shaped power receptacle 602is fitted within and supported by the primary housing 634. Although theillustrated power receptacle 602 is bowl-shaped, the receptacle may havea variety of alternative constructions. For example, the bowl-shapedreceptacle 602 may be replaced by horizontal surface (not shown) uponwhich inductively powered devices can be placed or it may be replaced byone or more rings from which inductively powered devices can besuspended. As a further example, the receptacle may be a verticalsurface adjacent to which various inductive devices can be suspended,such as an inductively powered wall lamp or an inductively poweredclock.

As noted above, the illustrated power supply station 600 also includes astorage receptacle 608 mounted to legs 606 a-c, for example, by screwsor other fasteners. The storage receptacle 608 provides a place forstoring lamp assemblies, such as lamp assembly 614 c, and otherinductively powered devices when they are not in use. In thisembodiment, the storage receptacle 608 is bowl-shaped, to complement theshape of the power receptacle 602, and is mounted between the legs 606a-c of the station 600 below the power receptacle 602 and above the base612. The size, shape, configurations and location of the storagereceptacle may vary from application to application as desired.Alternatively, the storage receptacle 608 may be eliminated.

The power supply station 600 also includes a power supply circuit 618that supplies power to a primary 620. In the illustrated embodiment, thepower supply circuit 618 is disposed within lamp base 612. Referring nowto FIG. 34, the lamp base 612 generally includes an upper housing 612 aand a lower housing 612 b that enclose the power supply circuit 618. Thepower supply circuit 618 includes a power switch 690 that is actuated bybutton 692. The button 692 extends down through a corresponding aperture694 in the upper housing 612 a to engage the switch 690. The button 692may be translucent and the power supply circuit 618 may include a pairof power-indicating LEDs 696 a-b that illuminate the button 692 when thepower is on. In this embodiment, a power supply cord 698 penetrates thelower housing 612 b and is electrically connected to power-in socket 699to provide AC power to the power supply circuit 618. Electrical leads(not shown) extend from the power supply circuit 618 to the primary 620through a wiring channel (not shown) in one of the legs 606 a-c. Thepower supply circuit 618 is preferably identical to power supply circuit18 described above. This power supply circuit 618 has the ability tomonitor the power supplied to the primary 620 to determine certaincharacteristics of the cumulative load (e.g. the inductively powereddevices placed in the power receptacle 602), and then to adjust thecharacteristics of the power supplied to the primary 620 as a functionof the monitored values. In one embodiment, the power supply circuit 618monitors the current supplied to the primary 620 and adjusts thefrequency of the power supplied to the primary 610 based on the value ofthe current.

In the illustrated embodiment, the inductively powered devices are aplurality of lamp assemblies 614 a-c. As perhaps best shown in FIG. 35,each of the lamp assemblies 614 a-c generally includes a lamp housing604 that encloses a light source 626 a-d and a secondary circuit 622. Inthis embodiment, the lamp housing 604 is assembled from two glass orinjection-molded plastic halves 604 a-b, at least one of which ismanufactured from a transparent or translucent material. The halves 604a-b are interconnected by cover ring 640, for example, by adhesives orthreads. A separate o-ring 642 a-b may be fitted between the cover ring640 and each half 604 a-b. The secondary circuit 622 is enclosed withinthe lamp housing 604, and generally includes a secondary 624 and anoptional capacitor 630 that are connected in series with light source626 a-d. In the illustrated embodiment, the light source includes aplurality of LEDs 626 a-d. In this embodiment, the secondary 624 has adiameter of 2 inches and includes 27 turns of 26-gauge straight wire 664wrapped circumferentially around a generally conventional plastic bobbin662. The characteristics of the secondary 624 (e.g. number of turns,diameter of coil, type of wire) and optional capacitor 630 (e.g.capacitance value) are selected to correspond with the light source 626a-d and the power supplied by the primary 620.

To improve the flexibility of the inductive power supply station, aninductive device may include a secondary having a plurality of coilsthat are arranged at different orientations. In applications where onlya single coil is used, it is possible that a device randomly placedwithin a power receptacle will be located with the coil orientedsubstantially parallel to the magnetic field. In such situations, thesecondary may not receive sufficient power to power the device from theprimary. The use of multiple coils addresses this problem by providing asecondary coil arrangement that significantly increases the likelihoodthat at least one coil will at least substantially intersect the fluxlines of the magnetic field generated by the primary. For example, aninductive device may include a secondary with two coils that areoriented at 90 degrees to one another. With this configuration, at leastone of the two coils is likely to extend across the flux lines of themagnetic field and receive power from the primary. The number ofseparate coils may vary from application to application, for example,the inductive device may include 3, 4, 6 or 8 coils at differentorientations to provide improved efficiency in a wide variety oforientations. By providing a sufficient number of coils at differentorientations, the inductive device can be configured to receive powerfrom the primary regardless of the orientation of the inductive device.

In one embodiment, the inductively power device includes a secondary 670having three separate coils 672 a-c; one oriented along each of the x, yand z axes of a Cartesian three-dimensional coordinate system. As shownin FIG. 36, an arrangement of three bobbins 660 a-c is provided toreceive the three coils 672 a-c. The diameters of the three bobbins 660a-c vary so that the bobbins 660 a-c can be fitted one within the other.Given that the power induced in a secondary is proportional to thediameter of the secondary, the use of differently sized bobbins mayresult in an imbalance in the power supplied to each secondary. Inapplications where it is desirable to balance the power induced in thedifferent coils 672 a-c, additional turns of wire can be added to thesmaller bobbins 660 b-c, with the precise number of additional turnsadded to each smaller bobbin depending primarily on its size. Forexample, if the outermost secondary 672 a includes seven turns, it maybe desirable to include eight turns on the middle secondary 672 b andnine turns on the innermost secondary 672 c. Alternatively, a sphericalbobbin (not shown) can be provided, with each coil being wrapped aboutthe spherical bobbin at the desired location and in the desiredorientation, for example, about the x, y and z axes. This embodimentreduces the differences in the diameters of the three secondaries,thereby improving the balance of the coils. Although the secondary withmultiple coils is described in connection with the inductively poweredlamp assembly 614, a secondary with multiple coils can be incorporatedinto essentially any inductively power device to maximize power transferin various orientations of the device within the magnetic field. Forexample, a cell phone (not shown) or personal digital assistant (notshown) can be provided with an inductively powered battery chargerhaving a secondary with a single coil, such as secondary 622 above, orwith multiple coils, such as secondary 670. In this example, a cellphone or personal digital assistant having a secondary with multiplecoils can be placed randomly within the power receptacle 602 withoutconcern for its orientation because the secondary 670 will be able toobtain sufficient power to charge the device in any orientation.

FIGS. 38 a-c show circuit diagrams for three embodiments of thethree-coil secondary 670. FIG. 38 a illustrates a circuit 680 thatprovides DC power from three separate coils 672 a-c. As shown, the threecoils 672 a-c are connected in parallel to the load, a capacitor 674 a-cis connected in series between each coil 672 a-c and the load. In thisembodiment, the value of each capacitor 674 a-c and each diode 676 a-cis selected to provide a resonant circuit for the load-side of thecircuit. This circuit 680 combines the power induced within each of thecoils using the capacitors to provide resonance with the load, anddiodes 674 a-c rectifying the voltage output from circuit 680.Alternatively, diodes 676 a-c can be eliminated from the circuit 680 toprovide AC power to the load.

FIG. 38 b illustrates a half wave rectifier circuit 680′ that providesDC power from three separate coils 672 a-c′. As shown, the three coils672 a-c′ are connected in parallel to the load through an arrangement ofdiodes 676 a-f′ is connected in series between each coil 672 a-c′ andthe load. In this embodiment, the value of each diode 676 a-f′ isdetermined based primarily on the characteristics of the load.Additionally, a capacitor 674 a-c′ is connected in series between oneside of the coil 672 a-c′ and the corresponding diodes 676 a-f′. Thevalue of each capacitor 674 a-c′ is also determined based primarily onthe characteristics of the load. This circuit 680′ combines the powerinduced within each of the coils using the capacitors to provideresonance with the load, and diodes 676 a-c rectifying the voltageoutput from the circuit 680′.

FIG. 38 c illustrates a full wave rectifier circuit 680″ that providesDC power from three separate coils 672 a-c″. As shown, the three coils672 a-c″ are connected in parallel to the load through an arrangement ofdiodes 676 a-l″ is connected in series between each coil 672 a-c″ andthe load. In this embodiment, the value of each diode 676 a-l″ isdetermined based primarily on the characteristics of the load.Additionally, a capacitor 674 a-c″ is connected in series between oneside of the coil 672 a-c″ and the corresponding diodes 676 a-l″. Thevalue of each capacitor 674 a-c″ is determined based primarily on thecharacteristics of the load. All three of these circuit 680, 680′ and680″ perform the function of providing DC power. Circuit 680 is likelythe least expensive design, while circuit 680″ provides the best controlover the DC output, for example, circuit 680″ likely provide lessfluctuation in the output compared to the other two embodiments.

In use, the illustrated inductive power supply station 600 andaccompanying light assemblies 614 a-c provide a distinctive andaesthetically pleasing light source. The amount and character of lightcast by the system can be adjusted by varying the number of lampassemblies 614 a-c placed within the receptacle 602, by varying theposition of each lamp assembly 614 a-c and by varying the orientation ofeach lamp assembly 614 a-c within the receptacle. For example,additional lamp assemblies 614 a-c can be added to the receptacle toincrease the brightness of light cast by the system. Similarly, thelocation or orientation of a given lamp assembly 614 a-c can be variedto control the light output of that particular lamp assembly 614 a-c.

In an alternative embodiment, the lamp assembly 614 includes two lightsources 626 a-b that are connected to separate secondaries 624 a-b (SeeFIG. 37). In this embodiment, the two light sources 626 a-b arepreferably light emitting diodes, each generating light of a differentcolor. The secondaries 624 a-b are oriented 90 degrees from each otherso that the power supplied to one secondary is inversely proportional tothe power supplied to the other secondary. For example, by rotating thelamp assembly 614 with the power receptacle 602, one secondary is movedinto a position that more directly intersects the magnetic fieldgenerated by the primary 620 while the other is moved to a position thatless directly intersects the magnetic field. As a result, the lampassembly 614 can be rotated within the power receptacle 602 toselectively control the color of the lamp assembly 614 by adjusting theamount of power supplied to each light source 626 a-b. For example, withred and blue light sources, the lamp assembly 614 can be rotated to castlight ranging from pure red through purple to pure blue. If desired, adevice can be provided with 3 separate secondaries, each oriented 90degrees from one another, such as along each of the x, y and z axes of aCartesian three-dimensional coordinate system. In accordance with thisalternative, each secondary can drive a separate light source or power aseparate electrical device. It should also be noted that the 3 axisconfiguration can be used to calculate the orientation of the device bycomparing the voltages from each secondary. In some applications, it maybe desired to provide an inductively powered device with two sets ofcoils, a first to set to provide power to one or more devices and asecond to provide position information. FIGS. 39 a-d illustrate circuitdiagrams for various multiple secondary circuits. FIG. 39 a illustratesa simple three secondary circuit 700 in which each coil 702 a-c isconnected to a separate load, such as a light source, a single channelof a three-channel position calculating circuit or other inductivelypowered device. FIG. 39 b illustrates an alternative circuit 710 inwhich a capacitor 714 a-c is connected in series between each secondary712 a-c and its corresponding load. In this embodiment, the capacitancevalue of each capacitor 714 a-c is selected primarily as a function ofthe corresponding load and the inductance of the corresponding secondaryto tune the power within each secondary circuit. FIG. 39 c illustratesan alternative circuit 720 in which a capacitor 724 a-c and a diode 726a-c are connected in series between each secondary 722 a-c and itscorresponding load. This circuit 720 provides limited rectification toprovide a separate source of DC power to each load. In this embodiment,the capacitance value of each capacitor 724 a-c and diode 726 a-c isselected primarily as a function of the corresponding load and theinductance of the corresponding secondary. FIG. 39 d illustrates analternative circuit 730 in which a capacitor 734 a-c and a pair ofdiodes 736 a-f are connected in series between each secondary 732 a-cand its corresponding load. This circuit 730 provides half waverectification to provide a separate source of DC power to each load. Inthis embodiment, the capacitance value of each capacitor 724 a-c anddiode 726 a-c is selected primarily as a function of the correspondingload and the inductance of the corresponding secondary. Although notillustrated, each secondary may alternatively include a full waverectification circuit to provide a separate source of DC power to eachload.

Although the inductive power supply station 600 is illustrated inconnection with a unique lamp construction, the inductive devices mayinclude other types of inductively powered devices. For example, a cellphone, personal digital assistant or other similar device may include aninductively powered battery charger that is configured to receive powerfrom the inductive power supply station. In such applications, theinductively powered devices can be charged simply by placing it withinthe power receptacle. The inductively powered device may use the powersupplied by the secondary to directly power, rather than simplerecharge, the device. For example, a miniature radio, MP3 music playeror other media player can be provided with inductive secondary circuits,permitting them to be powered by the power supply station.

The above description is that of a preferred embodiment of theinvention. Various alterations and changes can be made without departingfrom the spirit and broader aspects of the invention as defined in theappended claims, which are to be interpreted in accordance with theprinciples of patent law including the doctrine of equivalents. Anyreference to claim elements in the singular, for example, using thearticles “a,” “an,” “the” or “said,” is not to be construed as limitingthe element to the singular.

1. An inductively powered light assembly comprising: a primary coilgenerating a magnetic field; a lamp assembly including: a light source;a housing having a first light transparent portion that is at leastpartially light transparent and a second light transparent portion thatis at least partially light transparent, said first light transparentportion having different light transparency characteristics from saidsecond light transparent portion; wherein said lamp assembly ismountable within said magnetic field in at least two distinctorientations.
 2. The light assembly of claim 1 wherein said first lighttransparent portion is substantially transparent and said second lighttransparent portion is substantially translucent.
 3. The light assemblyof claim 1 wherein said first light transparent portion is larger thansaid second light transparent portion.
 4. The light assembly of claim 1wherein at least one of said first light transparent portion and saidsecond light transparent portion is a lens.
 5. The light assembly ofclaim 1 wherein said first light transparent portion is substantiallytranslucent and said second light transparent portion is substantiallytranslucent.
 6. The light assembly of claim 1 wherein said first lighttransparent portion is a first color and said second light transparentportion is a second color, said first color being different from saidsecond color.
 7. The light assembly of claim 1 further comprising asupport mounted substantially within the circumference of said primarycoil, said lamp assembly being mountable to said support in at least twodistinct orientations.
 8. The light assembly of claim 7 wherein saidfirst light transparent portion is directed substantially downwardlywhen said lamp assembly is mounted to said support in a firstorientation; and wherein said second light transparent portion isdirected substantially downwardly when said lamp assembly is mounted tosaid support in a second orientation.
 9. The light assembly of claim 8wherein said support defines an opening, said lamp assembly beingfittable within said opening in at least two distinct orientations. 10.An inductively powered light assembly comprising: a primary coilgenerating a magnetic field; a lamp assembly including: a light source;a housing having a first light transmissive portion that is at leastpartially light transmissive and a second light transmissive portionthat is at least partially light transmissive, said first lighttransmissive portion having different light transmissive characteristicsfrom said second light transmissive portion; and wherein said lampassembly is mountable within said magnetic field in at least twodistinct orientations; a support mounted substantially within thecircumference of said primary coil, said lamp assembly being mountableto said support in at least two distinct orientations, wherein saidfirst transmissive portion is directed substantially downwardly whensaid lamp assembly is mounted to said support in a first orientation,wherein said second transmissive portion is directed substantiallydownwardly when said lamp assembly is mounted to said support in asecond orientation, wherein said support defines an opening, said lampassembly being fittable within said opening in at least two distinctorientations; and wherein said lamp assembly includes a support ringengaging said support to support said lamp assembly within said openingwhen said lamp assembly is in said first orientation and said secondorientation.
 11. An inductively powered light assembly comprising: aprimary coil generating a magnetic field; a lamp assembly including: alight source; a housing having a first light transparent portion and asecond light transparent portion, said first light transparent portionhaving different light transparency characteristics from said secondlight transparent portion; and wherein said lamp assembly is mountablewithin said magnetic field in at least a first orientation and adistinct second orientation, such that in said first orientation atleast said first light transparent portion is exposed and in said secondorientation at least said second light transparent portion is exposed.12. The light assembly of claim 11 wherein said first light transparentportion is substantially transparent and said second light transparentportion is substantially translucent.
 13. The light assembly of claim 11wherein said first light transparent portion is larger than said secondlight transparent portion.
 14. The light assembly of claim 11 wherein atleast one of said first light transparent portion and said second lighttransparent portion is a lens.
 15. The light assembly of claim 11wherein said first light transparent portion is substantiallytranslucent and said second light transparent portion is substantiallytranslucent.
 16. The light assembly of claim 11 wherein said first lighttransparent portion is a first color and said second light transparentportion is a second color, said first color being different from saidsecond color.